<?php
/**
 * This file is part of the PQP package.
 * Copyright (C) 2017 pengzhile <pengzhile@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

namespace PQP\Contracts;

use SplQueue;

abstract class Process
{
    /**
     * @var bool
     */
    protected $running = false;

    /**
     * @var SplQueue
     */
    private $signalQueue;

    /**
     * @var array
     */
    protected $caredSignals = array();

    /**
     * @return SplQueue
     */
    protected function getSignalQueue()
    {
        null === $this->signalQueue && $this->signalQueue = new SplQueue();

        return $this->signalQueue;
    }

    protected function installSignals()
    {
        foreach ($this->caredSignals as $signal) {
            pcntl_signal($signal, array($this, 'signalHandler'));
        }
    }

    protected function restoreSignals()
    {
        foreach ($this->caredSignals as $signal) {
            pcntl_signal($signal, SIG_DFL);
        }
    }

    /**
     * @param int $signal
     */
    protected function signalHandler($signal)
    {
        $this->getSignalQueue()->enqueue($signal);
    }

    protected function dispatchSignals()
    {
        pcntl_signal_dispatch();

        if ($this->getSignalQueue()->isEmpty()) {
            $this->blankSignal();

            return;
        }

        $this->withSignals();
    }

    protected function blankSignal()
    {

    }

    abstract protected function withSignals();
}